In order for a pillow to function as a superior sleep aid, to allow a user to complete a higher percentage of sleep cycles including the highest percentage of REM sleep as possible, a pillow must: allow for and maintain the correct spinal alignment; provide a soft support for the entire neck and head area; and minimize the motion of fill material due to the weight of the head and neck. The above requirements are difficult to accomplish simultaneously in a pillow. While some of these objectives can be met in pillows which are traditionally soft or hard, such pillows are deficient in accomplishing all these desired objectives.
When using a soft pillow over a short period of time, correct spinal alignment is not maintained, resulting in spinal suppression/extension problems and associated muscular problems as the muscles attempt to maintain the head in its normal position or muscles remain stretched in a non-ordinary manner. Soft pillows frequently require the fill to be fluffed often which prevents continuous neck and head support. Such soft pillows also do not provide for minimization of fill movement due to the weight of the head and neck. Soft pillows also compress/compact rapidly over multiple periods of use, and lose their original size/thickness definition rapidly.
Hard pillows on the other hand, present a different set of problems. Although hard pillows provide a more stable platform for spinal alignment, the correct thickness of the pillow becomes an important consideration. The user's neck and head area will only be comfortable if the pillow is fitted or specifically designed for the particular neck/head configuration of the user. The neck muscles are sensitive to inordinate stretches and compressions created by an improperly sized pillow, which results in variations in the desired spinal alignment. Therefore, hard pillows quickly fail to achieve the necessary spinal alignment unless such a pillow is molded or shaped to fit the exact head/neck configuration of the user. The desired soft support for the neck and head area of the user is generally not achieved by such hard pillows. Further, the desired requirement of minimal fill movement is generally not achieved if a hard pillow does not match the user's particular body configuration.
A need has also arisen for a pillow that allows for and maintains correct spinal alignment while providing for soft support for the entire neck and head area of the user while simultaneously minimizing fill movement due to the weight of the head and neck of the user.